Tool holding structure for punching machine



y 1969 P. CADY, JR, ET AL 3,456,542

TOOL HOLDING STRUCTURE FOR PUNCHING MACHINE Filed Sept. 25, 1967 lllllflllllllll' United States Patent US. Cl. 83-635 9 Claims ABSTRACT OF THE DISCLOSURE A punching machine has a removable tool support which guides reciprocable tooling, there being horizontally acting clamps between the tool support and the frame of the machine, and vertically acting clamps between the tool support and the frame of the machine.

BACKGROUND Field of the invention This invention relates generally to punch press types of machine tools, and more specifically to a tool support for reciprocable tooling which is detachably a part of such machine-tool.

Prior art In US. Patent No. 3,270,605, there is shown a punching machine which has a tool support that is detachably secured thereto by a pair of manually-releasable horizontally-acting clamp means. Experience has shown that the structure in this patent operates Well and is adequate for all normal punching. However, when certain types of noncircular holes are to be punched, a problem has arisen. In particular, when it has been necessary to employ a tool which because of the shape of its cutting edge causes a non-uniform load distribution, there has been a tendency for certain punches to break. As an example, if instead of a piercing punch there is used a notching punch, the reactive load is non-uniformly distributed and there has been a tendency for such punch to break.

One solution that we have found for this problem is to make an appropriate change in the design of the punch, but such a solution to the problem is not desirable from a cost standpoint.

SUMMARY In accordance with our invention, we have determined that the breakage has been caused by a slight front-to-rear rocking of the tool support, and we have therefore modified the prior combination to include a second pair of manually-releasable clamps which act vertically. We have provided these clamps in a manner which entails a minimum of cost, and which provides ease of manual operation, without impairing any of the prior functions and advantages of the prior structure shown in Patent No. 3,270,605.

Accordingly, it is an object of the present invention to provide means for preventing the breakage of asymmetrical tooling when used in the combination described.

Another object of the present invention is to provide means by which a tool support is precluded from rocking when subjected to asymmetrical loads.

Yet a further object of the present invention is to provide vertical clamp means on the detachable tool support which forms part of a punch press.

Many other advantages, features and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying drawing in which a preferred structural embodiment incorporating the principles 3,456,542 Patented July 22, I969 "ice of the present invention is shown by way of illustrative example.

On the drawing:

FIG. 1 is a front elevational view of a tool support which forms a part of a punch press, provided in accordance with the principles of the present invention; and

FIG. 2 is a cross-sectional view taken along line II--II of FIG. 1.

As shown on the drawing:

The principles of the present invention are particularly useful when embodied in a punch press of the type shown in US. Patent No. 3,270,605, a relevant portion of which has been modified by ourselves to include a normally stationary tool support shown in FIG. 1, generally indicated by the numeral 10. The punch press includes a reciprocable ram 11 which lies between arms of the tool support 10, and which is aligned with an assembly of reciprocable tooling 12 which coacts with a fixed die 13. The tool support 10, as in the earlier form, is clamped to a pair of fixed slotted frame portions 14, 15 which are adjacent to the ram 11 at opposite sides thereof.

The tool support 10 includes a pair of vertical pins 16, 17 secured to the tool support 10 as described below, the pins 16, 17 being received in the slot of the slotted frame portions 14, 15 respectively, and being clamped at the inner or rearward end of such slots by a pair of manuallyreleasable horizontally-acting clamp means 18, 19 which are only fragmentarily illustrated. The details of the horizontally-acting clamp means 18, 19 are shown in Patent No. 3,270,605. For the purpose of understanding the present invention, it is sufficient to explain that when the clamp means 18, 19 are released, the pins 16, 17 are not retained and the tool support 10 is free to move toward the viewer as shown in FIG. 1 and to move toward the left as shown in FIG. 2. Such movement is precluded when the clamp means 18, 19 are in a clamped position. Thus, the clamp means 18, 19 are carried by the frame of the punch press and act on the pins 16, 17 in a horizontal direction to prevent horizontal movement of the tool support 10 and hence to prevent horizontal movement of the tooling 12.

When the tooling 12 has a cutting edge of a shape that imparts an asymmetrical load to the tool support 10, there is a tendency for the lower end of the tool support 10 to rock about a horizontal axis and thus to subject the tooling to a risk of breakage. Such movement in accordance with our invention is precluded by a second pair of manually-releasable clamp means which act vertically, one such clamp means being identified by the numeral 20 and the other by the numeral 21. The clamp means 20, 21 are carried by the tool support 10 and hold it firmly against the slotted frame portions 14, 15, thereby preventing any rocking about a horizontal axis.

The clamp means 20 is identical to the clamp means 21, except for a minor feature, and the description therefore for the clamp means 21 is applicable to both. The vertical pins 16, 17 have threads on their lower ends as at 22 which extend through the tool support 10 and which in this embodiment project below such tool support. A pair of threaded handles 23 are respectively carried on the pins 16, 17 in threaded engagement therewith. The upper ends of the pins 16, 17 are provided with enlarged heads in the form of a pair of separate bushings 24 which are fixedly secured to the upper ends of the pins 16, 17. The upper end of each pin 16, 17 is provided with a small head 25 which is received within the bushing 24 so that when the pins 16, 17 are tensioned, the bushing 24 is drawn downwardly so as to positively engage a lower shoulder 26 with the upper surface of the slotted frame portion 14, 15. A set screw 27 carried by the bushing 24 prevents any rotation of the screws 16, 17, and a further set screw or keying means 28 is carried by the upper arm 29 of the tool support 10 and extends into a slot 30 in the bushing 24 to prevent any rotation of the bushing. The inner end of the set screw or keying means 28 is received in the slot 30 so that the bushing 24, which is otherwise guided in a bore 31 in the upper arm 29 is free to move axially but not angularly. This movement is in a relative sense when a slight amount of movement does take place since it is the tool support that shifts slightly, as explained below.

A pair of springs 32 act between the upper side of the tool support and the bushing 24 so as to relatively urge the bushing 24 away from the slotted frame portion 15. This function can also be described in another sense. When the horizontally acting clamp means 19 is released, and the tool support has been moved away from the slotted frame portion 15, the spring 32 acts to hold the bushing 24 in an elevated position so that on re-assembly, the lower edge of the bushing 24 will not strike the forward upper leading edge of the slotted portion 15.

When the tool support is placed on the slotted frame portions 14, 15, it is in effect suspended thereon in that the upper arm 29 rests on the upper surface of the slotted frame portion as shown in FIG. 1. All the clearance in a vertical direction that is present will therefore be present immediately beneath the slotted frame portion 15, as also shown in FIG. 1. When the second or vertical clamp means 21 is tightened, the clamp means 21 acts between the upper side of the slotted frame portion 15 and the lower side of the tool support 10, thus taking up such clearance and firmly drawing the tool support 10 against the lower side of the slotted frame portion 15. This condition is illustrated in FIG. 2 where a relatively large area such as indicated by the numeral 33 provides the necessary stability.

It is preferable to include a lock washer 34. The threads of the pin 16 are usually and preferably made to be of the opposite hand from the threads on the pin 17. Thus one set of threads 22 may be conventional right-hand threads while the threads of the other pin would be left-hand threads, or vice versa depending on where it was desired that the handle 23 should repose in the clamped position. Once the clamps 20, 21 have been tightened, the device may be employed with tooling 12 having an asymmetrical shape, such as notching tooling, without risk of damage to the punch.

Although various minor modifications might be suggested by those versed in the art, it should be understood that we wish to embody within the scope of the patent warranted hereon, all such embodiments as reasonably and properly come within the scope of our contribution to the art.

We claim as our invention:

1. In a punch press having a reciprocable ram, a pair of fixed slotted frame portions adjacent to said ram at opposite sides thereof, a stationary tool support for supporting reciprocable tooling in alignment with the lower surface of said ram and having a pair of vertical pins respectively disposed in the slots of said slotted frame.

portions, 21 pair of manually-releasable horizontally-acting clamp means carried by said frame for engaging and firmly holding said pins against said frame portions to prevent any horizontal movement of said tool support, the improvement comprising a second pair of manuallyreleasable vertically-acting clamp means, carried by said tool support for firmly holding said tool support against said frame portions to prevent any rocking thereof about a horizontal axis in response to use of tooling of an asymmetrical shape.

2. A punch press according to claim 1, wherein said second clamp means comprises threaded ends of said vertical pins projecting through said tool support, and a pair of threaded handles carried on said threaded ends and manually movable into firm engagement with the adjacent side of said tool support.

3. A punch press according to claim 2 wherein said threaded ends of said vertical pins project beneath said tool support, and said threaded handles extend beneath said tool support.

4. A punch press according to claim 1, wherein said second pair of clamp means urges said tool support firmly against a lower side of said slotted frame portion.

5. A punch press according to claim 2, wherein said vertical pins, remotely from their threaded ends, have enlarged heads extending through said tool support, said heads having a shoulder engageable with said slotted frame portions.

6. A punch press according to claim 5, wherein means act between said tool support and said enlarged heads for preventing rotation of said pins.

7. A punch press according to claim 5, wherein said enlarged heads are separate bushings corotatably secured to said vertical pins, and keying means acting between said tool support and said enlarged heads for enabling relative axial movement but precluding rotation of said bushings.

8. A punch press according to claim 5, wherein said enlarged heads are axially slidably guided by said tool support, and springs acting between said enlarged heads and said tool support and urging said enlarged heads away from said slotted frame portions.

9. A punch press according to claim 1, wherein said second clamp means comprises:

(a) threads on the lower ends of said vertical pins projecting below said tool support;

(b) a pair of threaded handles in threaded engagement with said vertical pins for acting on the lower side of said tool support;

(c) a pair of enlarged bushings fixedly secured to the upper ends of said vertical pins and guided for axial sliding and against rotation by said tool support, said bushings being engageable with the upper side of said slotted frame portions; and

(d) a pair of springs acting between said bushings and said tool support and urging said bushings away from said slotted frame portions; whereby when said second clamp means are released, said tool support is suspended on the upper side of said slotted frame portions, and when said second clamp means are tightened, said tool support is clamped against the underside of said slotted frame portions.

References Cited UNITED STATES PATENTS 3,270,605 9/1966 Schott et a1. 83-522 JAMES M. MEISTER, Primary Examiner US. Cl. X.R. 8.36,98 

